fs/nfs/mount_clnt.c

   1 /*
   2  * In-kernel MOUNT protocol client
   3  *
   4  * Copyright (C) 1997, Olaf Kirch <okir@monad.swb.de>
   5  */
   6
   7 #include <linux/types.h>
   8 #include <linux/socket.h>
   9 #include <linux/kernel.h>
  10 #include <linux/errno.h>
  11 #include <linux/uio.h>
  12 #include <linux/net.h>
  13 #include <linux/in.h>
  14 #include <linux/sunrpc/clnt.h>
  15 #include <linux/sunrpc/sched.h>
  16 #include <linux/nfs_fs.h>
  17 #include "internal.h"
  18
  19 #ifdef RPC_DEBUG
  20 # define NFSDBG_FACILITY        NFSDBG_MOUNT
  21 #endif
  22
  23 static struct rpc_program       mnt_program;
  24
  25 struct mnt_fhstatus {
  26         u32 status;
  27         struct nfs_fh *fh;
  28 };
  29
  30 /**
  31  * nfs_mount - Obtain an NFS file handle for the given host and path
  32  * @addr: pointer to server's address
  33  * @len: size of server's address
  34  * @hostname: name of server host, or NULL
  35  * @path: pointer to string containing export path to mount
  36  * @version: mount version to use for this request
  37  * @protocol: transport protocol to use for thie request
  38  * @fh: pointer to location to place returned file handle
  39  *
  40  * Uses default timeout parameters specified by underlying transport.
  41  */
  42 int nfs_mount(struct sockaddr *addr, size_t len, char *hostname, char *path,
  43               int version, int protocol, struct nfs_fh *fh)
  44 {
  45         struct mnt_fhstatus     result = {
  46                 .fh             = fh
  47         };
  48         struct rpc_message msg  = {
  49                 .rpc_argp       = path,
  50                 .rpc_resp       = &result,
  51         };
  52         struct rpc_create_args args = {
  53                 .protocol       = protocol,
  54                 .address        = addr,
  55                 .addrsize       = len,
  56                 .servername     = hostname,
  57                 .program        = &mnt_program,
  58                 .version        = version,
  59                 .authflavor     = RPC_AUTH_UNIX,
  60                 .flags          = 0,
  61         };
  62         struct rpc_clnt         *mnt_clnt;
  63         int                     status;
  64
  65         dprintk("NFS: sending MNT request for %s:%s\n",
  66                 (hostname ? hostname : "server"), path);
  67
  68         mnt_clnt = rpc_create(&args);
  69         if (IS_ERR(mnt_clnt))
  70                 goto out_clnt_err;
  71
  72         if (version == NFS_MNT3_VERSION)
  73                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
  74         else
  75                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MNTPROC_MNT];
  76
  77         status = rpc_call_sync(mnt_clnt, &msg, 0);
  78         rpc_shutdown_client(mnt_clnt);
  79
  80         if (status < 0)
  81                 goto out_call_err;
  82         if (result.status != 0)
  83                 goto out_mnt_err;
  84
  85         dprintk("NFS: MNT request succeeded\n");
  86         status = 0;
  87
  88 out:
  89         return status;
  90
  91 out_clnt_err:
  92         status = PTR_ERR(mnt_clnt);
  93         dprintk("NFS: failed to create RPC client, status=%d\n", status);
  94         goto out;
  95
  96 out_call_err:
  97         dprintk("NFS: failed to start MNT request, status=%d\n", status);
  98         goto out;
  99
 100 out_mnt_err:
 101         dprintk("NFS: MNT server returned result %d\n", result.status);
 102         status = nfs_stat_to_errno(result.status);
 103         goto out;
 104 }
 105
 106 /*
 107  * XDR encode/decode functions for MOUNT
 108  */
 109 static int xdr_encode_dirpath(struct rpc_rqst *req, __be32 *p,
 110                               const char *path)
 111 {
 112         p = xdr_encode_string(p, path);
 113
 114         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 115         return 0;
 116 }
 117
 118 static int xdr_decode_fhstatus(struct rpc_rqst *req, __be32 *p,
 119                                struct mnt_fhstatus *res)
 120 {
 121         struct nfs_fh *fh = res->fh;
 122
 123         if ((res->status = ntohl(*p++)) == 0) {
 124                 fh->size = NFS2_FHSIZE;
 125                 memcpy(fh->data, p, NFS2_FHSIZE);
 126         }
 127         return 0;
 128 }
 129
 130 static int xdr_decode_fhstatus3(struct rpc_rqst *req, __be32 *p,
 131                                 struct mnt_fhstatus *res)
 132 {
 133         struct nfs_fh *fh = res->fh;
 134         unsigned size;
 135
 136         if ((res->status = ntohl(*p++)) == 0) {
 137                 size = ntohl(*p++);
 138                 if (size <= NFS3_FHSIZE && size != 0) {
 139                         fh->size = size;
 140                         memcpy(fh->data, p, size);
 141                 } else
 142                         res->status = -EBADHANDLE;
 143         }
 144         return 0;
 145 }
 146
 147 #define MNT_dirpath_sz          (1 + 256)
 148 #define MNT_fhstatus_sz         (1 + 8)
 149 #define MNT_fhstatus3_sz        (1 + 16)
 150
 151 static struct rpc_procinfo mnt_procedures[] = {
 152         [MNTPROC_MNT] = {
 153                 .p_proc         = MNTPROC_MNT,
 154                 .p_encode       = (kxdrproc_t) xdr_encode_dirpath,
 155                 .p_decode       = (kxdrproc_t) xdr_decode_fhstatus,
 156                 .p_arglen       = MNT_dirpath_sz,
 157                 .p_replen       = MNT_fhstatus_sz,
 158                 .p_statidx      = MNTPROC_MNT,
 159                 .p_name         = "MOUNT",
 160         },
 161 };
 162
 163 static struct rpc_procinfo mnt3_procedures[] = {
 164         [MOUNTPROC3_MNT] = {
 165                 .p_proc         = MOUNTPROC3_MNT,
 166                 .p_encode       = (kxdrproc_t) xdr_encode_dirpath,
 167                 .p_decode       = (kxdrproc_t) xdr_decode_fhstatus3,
 168                 .p_arglen       = MNT_dirpath_sz,
 169                 .p_replen       = MNT_fhstatus3_sz,
 170                 .p_statidx      = MOUNTPROC3_MNT,
 171                 .p_name         = "MOUNT",
 172         },
 173 };
 174
 175
 176 static struct rpc_version mnt_version1 = {
 177         .number         = 1,
 178         .nrprocs        = 2,
 179         .procs          = mnt_procedures,
 180 };
 181
 182 static struct rpc_version mnt_version3 = {
 183         .number         = 3,
 184         .nrprocs        = 2,
 185         .procs          = mnt3_procedures,
 186 };
 187
 188 static struct rpc_version *mnt_version[] = {
 189         NULL,
 190         &mnt_version1,
 191         NULL,
 192         &mnt_version3,
 193 };
 194
 195 static struct rpc_stat mnt_stats;
 196
 197 static struct rpc_program mnt_program = {
 198         .name           = "mount",
 199         .number         = NFS_MNT_PROGRAM,
 200         .nrvers         = ARRAY_SIZE(mnt_version),
 201         .version        = mnt_version,
 202         .stats          = &mnt_stats,
 203 };